Corner region between the lateral and rear roof frames on a motor vehicle with a hatch back door and method for production thereof

ABSTRACT

The invention relates to a corner region between the lateral and rear roof frame of a motor vehicle having a rear door, and to a method for producing it. In order to improve the absorption of mechanical forces acting on the body shell in the roof region in a simple manner, it is proposed to form the corner region from shell-shaped components of the rear roof frame and a D-pillar of the motor vehicle and from a hollow profile formed by internal high pressure, the components and the hollow profile being connected nonreleasably to one another. The hollow profile is designed as a junction component which, with a first, open end, is connected to the D-pillar, with a closed neck aligned with the first, open end, is connected to the shell components of the lateral roof frame and, with a second, open end which is angled away from the longitudinal section of the hollow profile, which extends from the first, open end beyond the neck, is connected to the components of the rear roof frame.

BACKGROUND AND SUMMARY OF THE INVENTION

This invention relates to a corner region between the lateral and rearroof frame of a motor vehicle having a rear door, and to a method forproducing it.

In conventional motor vehicles having a rear door, a large number ofplates are used in the body shell in order to confer the requiredstiffness and strength of the corner region between the lateral and therear roof frame, since the corner region, which comprises sheet-metalshells of the lateral roof frame, is open toward the rear of the vehiclein order to hold a hinge for the rear door and is therefore weakened. Inthis case, work has to be carried out in a very complex manner withseam-sealing material in order to prevent water which penetrates intothe hinge opening from being able to pass into the interior of thevehicle and the rest of the body shell.

The invention is based on the object of developing a corner regionbetween the lateral and rear roof frame of a motor vehicle having a reardoor and a method for producing it to the effect that the absorption ofmechanical forces acting on the body shell in the roof region isimproved in a simple manner.

This object is achieved according to the invention by the features ofclaim 1 in respect of the corner region and by the features of claim 10in respect of the production method.

Owing to the fact that a junction component consisting of a hollowprofile is used for the corner region, high stiffness and strength isprovided for this region. This is all the more so if the hollow profileis a single-piece component which is formed from a tubular blank.Single-piece formation means that the body shell is very greatlysimplified structurally and in terms of manufacturing at this point andthe multiplicity of parts is drastically reduced, and at the same timeforces which act from the outside, in particular in a crash, can beconsiderably better absorbed by the lateral and rear roof frame and theD-pillar and can be transferred without stress concentrations. It istrue that because the hollow profile is closed seamlessly in thedirection of the front end of the vehicle, water can enter into thehollow profile through the rearwardly pointing opening. However, furtherpenetration through the body shell and penetration into the interior ofthe vehicle is not possible, and so the only route for the water toleave is the inlet opening. This considerably reduces the outlay onsealing, which is now focused entirely on the inlet opening. Thetechnique of forming by internal high pressure means that the hollowprofile can be matched exactly to the desired space-dependent shape andcross section in a relatively simple manner in terms of the process.

Expedient refinements of the invention can be gathered from thesubclaims; otherwise, the invention is explained in greater detail belowwith reference to an exemplary embodiment which is illustrated in thedrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows, schematically in a perspective illustration, a motorvehicle having a corner region according to the invention of the lateraland rear roof frame,

FIG. 2 shows, in a sectional illustration, part of the corner regionaccording to the invention from FIG. 1 with the lateral and rear roofframe and a D-pillar, and

FIG. 3 shows, in a lateral longitudinal section, the corner region fromFIG. 1 with a hinge system arranged on the inside.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 illustrates the rear side of a motor vehicle 1, the rear door 2of which is fitted into the frame bounded by two D-pillars 3 (only theleft-hand one is shown here), and the rear roof frame 4. A lateral roofframe 5 is connected to the D-pillar 3 and to the rear roof frame 4 inthe roof region toward the front end of the vehicle. The D-pillar 3 andthe rear roof frame 4 and the lateral roof frame 5 are connected to oneanother by a junction component 6 which occupies the connecting regionin a three-dimensional manner.

According to FIG. 2, the rear roof frame 4 comprises two shell-shapedcomponents, i.e. an upper half shell 7 and a lower half shell 8 having astep-shaped profile, which are connected nonreleasably, preferablywelded or bonded, to each other to form a box-shaped hollow profile. Theupper half shell 7 has a flange 9 which protrudes toward the rear of thevehicle, is formed by the lower step of said half shell and the edge 10of which is repositioned upward. The bottom section 11 of the flange 9forms, in a functionally favorable and component-saving manner togetherwith the repositioned edge 10 and the front wall 12, which is likewiseformed by the upper half shell and connects the two steps to each other,a channel-like holder 13 for a frame seal. The D-pillar 3, the holder 14of which merges into the holder 13 of the rear roof frame 4, is formedin a corresponding manner.

On the end side together with the junction component 6, the half shells7 and 8 and the D-pillar 3 form the corner region 15 between the lateralroof frame 5 and rear roof frame 4. The junction component 6 is designedas an elongate hollow profile of rectangular cross section which, with afirst, open end 16, is connected to the D-pillar 3 and, with a closedneck 17 aligned with the first, open end 16, is connected toward thefront end of the vehicle to the shell components of the lateral roofframe 5. Furthermore, the junction component 6 has a second end 18 whichis angled away from its longitudinal section, which extends from thefirst, open end 16 beyond the neck 17, said second end, like the firstend 16 which is situated close to it, being open and being connected tothe half shells 7 and 8 of the rear roof frame 4. Said half shells, bymeans of their hollow-profile section, circumferentially cover thesecond, open end 18 while the shell components of the D-pillar 3circumferentially cover the first, open end 16, and the shell componentsof the lateral roof frame 5 circumferentially cover the neck 17 of thejunction component 6, with the formation of an overlapping zone 19. Inthe latter, the components are connected, preferably spot-welded, to thejunction component 6. For the exact transition of the holder 13 of therear roof frame 4 into the holder 14 of the D-pillar 3, the first, openend 16 of the junction component has a notch 20 which can be produced bya three-dimensional laser cut. Owing to the junction component 6 beingattached to the lateral and the rear roof frame and to the D-pillar 3 ina corresponding manner in terms of shape, a mechanical force acting fromthe outside can be particularly readily distributed in the body shellstructure, so that impact energy is very readily absorbed.

A further exceptional advantage of the corner region 15 according to theinvention is the use of the junction component 6 as a stiff receivinghousing for a hinge system. In this case, the spring-damped hingesystem, which is arranged within the junction component 6, comprises ahinge 21 for the rear door 2 and a hinge 22 for a tiltable rear window23 (FIG. 3). The two hinges 21 and 22 are mounted on the same horizontalrotating spindle 24 which is held at one end 25 of a bearing block 26which is fastened releasably, in particular screwed, to the bottom 27 ofthe junction component 6. With regard to the arrangement and design ofthe screw holes, the screw connection can take place in such a mannerthat the bearing block 26 on the bottom 27 of the junction component 6can be varied in the longitudinal and transverse directions of thevehicle 1, as a result of which the position of the hinge system can beadjusted, in the closed state of the rear door 2, in a rapid mannerwhich is not at all complicated in terms of the installation. Thisenables the size of the gap of the closing joint between the rear door 2and the frame surrounding the latter on the vehicle to be exactlydefined in a simple manner with individual adaptation to themanufacturing tolerances, which is of benefit to opening and closing therear door 2 without obstruction for as long as possible. Not only is thesimple adjustability an advantage arising from the invention, but so toois the installation of the hinge system in the hollow profile of thejunction component 6 which is not difficult on account of the easy,manual accessibility, the system, in the form of a module which ispreassembled on the bearing block, having merely to be inserted into thehollow profile and screwed on. This is also favorable in the event ofrepair, in which case a particular affected hinge 21, 22 and/or the reardoor 2 can be interchanged there rapidly and simply. Furthermore, thetwo hinges 21 and 22 of the hinge system are supported on differenthydraulic or pneumatic spring-damping elements, in “gas-filled springs”28 and 29. These are mounted pivotably at one end at the end 30 of thebearing block 26, which is situated close to the closed end 31 of theneck 17, and are fastened in an articulated manner at the other end to aprotruding sheet-metal tab 32, 33 of the respectively assigned hinge 21,22, respectively. Simple installation of the gas-filled springs 28 and29 on the bearing block 26 in a manner which saves on manufacturing timeis also produced by the invention, since, after the body shell is passedthrough the painting operation without the gas-filled springs 28, 29,which would otherwise become damaged in the painting heat and becomefunctionally impaired, said gas-filled springs have to be fittedsubsequently, which can be easily made possible by loosening the screwsand pulling out the bearing block 26. This causes paint scratches at thescrew-connection locations, but because they are situated deep withinthe junction component 6 they are advantageously optically invisible.The gas-filled springs 28, 29 may also be pushed into the junctioncomponent 6 and, via a lateral opening in the junction component 6,which opening is subsequently closed in a watertight manner by means ofa rubber stopper, pressed onto the spherical-headed mounting.

Advantages furthermore arise in the routing of electric supply andcontrol cables from the rear roof frame 4 into the junction component 6,and—from the latter—via the hinges 21 and 22 into the rear door 2, saidcable routing also being facilitated in respect of the outlay forwatertightness.

To produce the junction component 6 of the corner region 15, use is madeof a rectilinear tube which is subsequently bent in a knee-shaped mannerand then pinched into a profile preform, so that the angled tube obtainsa rectangular cross section. The cross-sectional shape can also bedifferent and can be adapted to the particular space conditions and/orthe particular requirements as desired. The profile preform is thenplaced into an internal high-pressure forming mold and is expanded inaccordance with the desired final shape by means of fluidic internalhigh pressure. At the same time, the neck 17 is blown out at thelocation of the knee-shaped bend, said neck running essentiallycoaxially with the opening 34 in the hollow profile that points towardthe rear of the vehicle in the installed position, and subsequentlyremaining closed. In this case, it is conceivable to allow the formingprocess of the neck 17 to take place in a number of steps, in which casethe hollow profile is subjected to intermediate annealing after eachstep in order to reliably make possible the large amount of strain whichexists at the given, large drawn-out length of the neck 17.

To produce the corner region 15, the shell-shaped components 7, 8 of therear roof frame and of the D-pillar 3 of the motor vehicle 1 are joinedonto the finished junction component 6. This can take place, firstly, byfirst of all the shell components 7 and 8 being welded to one another orbonded to one another forming a box-shaped hollow profile, after whichthe latter is then placed, in a simple manner in terms of the process,onto the open, second end 18 of the junction component 6. In thispreliminary fixed connection, a weld, preferably spot welds or apenetration weld by means of a high-energy beam, to the junctioncomponent 6 can then take place in the overlapping zone 19 of theplug-in connection. The hall-shell of the D-pillar 3 is placed onto thenotch 20 and is welded to the first, open end 16 of the junctioncomponent 6. Secondly, it is also conceivable to place the shellcomponents onto the circumference of the ends 16 and 18, thus producingthe overlapping zone 19 in which the joining then takes place by meansof welding. In this case, the connection of the shell components to oneanother to form a hollow profile can also take place, in a manner whichis economical for the process, in a welding operation. Finally, thespring-damped hinge system is pushed into the opening 34 in the junctioncomponent 6, which opening points toward the rear of the vehicle, and isfastened releasably, in particular screwed, for example by screws 40, tothe bottom 27 of said junction component.

1. A corner region between the lateral and rear roof frames of a motorvehicle having a rear door, the corner region comprising: shell-shapedcomponents of the rear roof frame, a D-pillar of the motor vehicle, anda hollow profile formed by internal high pressure, wherein thecomponents, the D-pillar, and the hollow profile are connectednon-releasably to one another, and wherein the hollow profile isdesigned as a junction component which, with a first, open end, isconnected to the D-pillar, with a closed neck aligned with the first,open end, is connected to shell components of the lateral roof frameand, with a second, open end which is angled away from the longitudinalsection of the hollow profile, which extends from the first, open endbeyond the neck, is connected to the components of the rear roof frame.2. The corner region as claimed in claim 1, wherein one of theshell-shaped components of the rear roof frame has a flange whichprotrudes toward the rear of the vehicle and which has an edge which isrepositioned upward, and which, together with the repositioned edge,forms a channel-like holder for a seal.
 3. The corner region as claimedin claim 1, wherein the shell-shaped components of the rear roof frameare connected to each other to form a box-shaped hollow profile.
 4. Thecorner region as claimed in claim 1, wherein the shell-shaped componentsof the rear roof frame circumferentially cover the second, open end,wherein the D-pillar circumferentially covers the first, open end, andwherein the lateral roof frame circumferentially covers the neck of thejunction component, with formation of overlapping zones in which theshell-shaped components of the rear roof frame are connected to thejunction component.
 5. The corner region as claimed in claim 1, whereina spring-damped hinge system comprising a hinge for the rear door and ahinge for a tiltable rear window is arranged within the junctioncomponent.
 6. The corner region as claimed in claim 5, wherein the hingesystem is fastened releasably to the bottom of the junction component.7. The corner region as claimed in claim 5, wherein the hinge system isheld on a bearing block which is fastened to the bottom of the junctioncomponent.
 8. The corner region as claimed in claim 7, wherein aposition of the hinge system on the bearing block can be varied in thelongitudinal and transverse directions of the vehicle.
 9. The cornerregion as claimed in claim 5, wherein the hinges of the hinge system aresupported on different hydraulic or pneumatic spring-damping elements.10. The corner region as claimed in claim 6, wherein the hinge system isscrewed to the bottom of the junction component.
 11. The corner regionas claimed in claim 2, wherein the shell-shaped components of the rearroof frame are connected to each other to form a box-shaped hollowprofile.
 12. The corner region as claimed in claim 2, wherein theshell-shaped components of the rear roof frame circumferentially coverthe second, open end, wherein the D-pillar circumferentially covers thefirst, open end, and wherein the lateral roof frame circumferentiallycovers the neck of the junction component, with formation of overlappingzones in which the shell-shaped components of the rear roof frame areconnected to the junction component.
 13. The corner region as claimed inclaim 3, wherein the shell-shaped components of the rear roof framecircumferentially cover the second, open end, wherein the D-pillarcircumferentially covers the first, open end, and wherein the lateralroof frame circumferentially covers the neck of the junction component,with formation of overlapping zones in which the shell-shaped componentsof the rear roof frame are connected to the junction component.
 14. Thecorner region as claimed in claim 2, wherein a spring-damped hingesystem comprising a hinge for the rear door and a hinge for a tiltablerear window is arranged within the junction component.
 15. The cornerregion as claimed in claim 14, wherein the hinge system is fastenedreleasably to the bottom of the junction component.
 16. The cornerregion as claimed in claim 14, wherein the hinge system is held on abearing block which is fastened to the bottom of the junction component.17. The corner region as claimed in claim 16, wherein a position of thehinge system on the bearing block can be varied in the longitudinal andtransverse directions of the vehicle.
 18. The corner region as claimedin claim 14, wherein the hinges of the hinge system are supported ondifferent hydraulic or pneumatic spring-damping elements.
 19. The cornerregion as claimed in claim 3, wherein a spring-damped hinge systemcomprising a hinge for the rear door and a hinge for a tiltable rearwindow is arranged within the junction component.
 20. The corner regionas claimed in claim 19, wherein the hinge system is fastened releasablyto the bottom of the junction component.
 21. The corner region asclaimed in claim 19, wherein the hinge system is held on a bearing blockwhich is fastened to the bottom of the junction component.
 22. Thecorner region as claimed in claim 21, wherein a position of the hingesystem on the bearing block can be varied in the longitudinal andtransverse directions of the vehicle.
 23. The corner region as claimedin claim 19, wherein the hinges of the hinge system are supported ondifferent hydraulic or pneumatic spring-damping elements.
 24. The cornerregion as claimed in claim 4, wherein a spring-damped hinge systemcomprising a hinge for the rear door and a hinge for a tiltable rearwindow is arranged within the junction component.
 25. The corner regionas claimed in claim 24, wherein the hinge system is fastened releasablyto the bottom of the junction component.
 26. The corner region asclaimed in claim 24, wherein the hinge system is held on a bearing blockwhich is fastened to the bottom of the junction component.
 27. Thecorner region as claimed in claim 26, wherein a position of the hingesystem on the bearing block can be varied in the longitudinal andtransverse directions of the vehicle.
 28. The corner region as claimedin claim 24, wherein the hinges of the hinge system are supported ondifferent hydraulic or pneumatic spring-damping elements.